1. Field of the Invention
The present invention relates to a tufted carpet. More specifically, the present invention relates to a tufted carpet in which a pile is tufted into a backing fabric woven of multifilament yarns used for warp and weft, and which is so dimensionally stable that it is not damaged when used in busy traffic areas, such as the floor of a vehicular passageway.
2. Discussion of the Related Art
Conventionally, a backing fabric is made of a flat yarn fabric that is woven of flat ribbon monofilament yarns, which are made of such plastics as polypropylene, polyester, and the like.
The flat ribbon monofilament yarn is very thin, like a film. The flat yarn fabric is closely woven without forming an opening among the warps and wefts.
During use of the flat yarn fabric, a needle has to accurately pass through the flat ribbon monofilament yarn. Then a pile is firmly clipped in the interstice that has been pierced in the flat ribbon monofilament yarn by the needle.
Even though the flat yarn fabric is so closely woven as to not form an opening among warps and wefts, it is still light weight and inexpensive due to the flatness and thinness of the warps and wefts. But the flat yarn fabric has a serious fault of being low in tensile strength and dimensional stability, because the tufting process requires that the flat ribbon monofilament yarn be so flat and thin so that it can be easily split and accurately pierced by the needle to form the interstice for clipping the pile.
A polyester multifilament fabric is also conventionally used for the backing fabric. The multifilament fabric is woven of polyester multifilament yarns used for warps and wefts and possesses a stronger tensile strength than the flat yarn fabric. Further, it is well known that the multifilament fabric is superior in flexibility to the flat yarn fabric, since its warp yarns and weft yarns are composed of multifilaments.
However, since the multifilament fabric is superior in flexibility, it tends to be forced in by a needle 22 between adjacent finger needles (20, 20) for supporting a backing fabric (11) in the tufting process, as shown in FIG. 5.
When the multifilament fabric, that is, the backing fabric (11) is forced in between adjacent finger needles (20, 20), longitudinal puckers (30) rise in the multifilament fabric.
In addition to longitudinal puckers (30), transverse puckers (32) also rise in the multifilament fabric during the tufting process for the polyester multifilament fabric on the fine gauge tufting machine (see FIG. 7). The transverse puckers (32) rise in the multifilament fabric (11).
Conventionally, in the fine gauge tufting machine, or in the case of making a needle gauge narrower, the staggered system, where the first needles and the second needles are aligned in a double lines longitudinally front and rear, is applied to the tufting machine, as disclosed in U.S. Pat. No. 4,658,739, the disclosure of which is hereby incorporated by reference.
In the staggered system, each adjacent first needles (22, 22) are partitioned with a finger needle (20) elongated rearward. The end portion (31) of the finger needle (20) diverges into a pair of tines. Each adjacent second needles (23, 23) are partitioned with the tine (31) of the finger needle (20) projecting from the interspace between adjacent first needles (22, 22), shown as in FIG. 6. This kind of diverged finger needle (20) is conventionally applied to various tufting machines of which a needle gauge is ⅛ inch, {fraction (5/32)} inch, and the like.
In the fine gauge tufting machine of which a needle gauge is less than {fraction (1/10)} inch, an interspace between adjacent needles is narrower than that of other gauge tufting machines, such as ⅛ inch gauge tufting machine, {fraction (5/32)} inch gauge tufting machine, and the like. Thus, the finger needle (20) applied to the fine gauge tufting machine should be formed by thinning it in accordance with the interspace between adjacent needles. The finger needle, thus, becomes flexible laterally back and forth in proportion to its thinness.
In regard to the fine gauge tufting machine of which a needle gauge is less than {fraction (1/10)} inch, it was considered to arrange the three kinds of needles comprising the first needles, the second needles and the third needles, in three lateral lines crossing the direction of the fabric feeding. In this manner, the end portion of the finger needle diverged to project between the adjacent second needles to partition them should be further diverged by bending twice or thrice to project between the adjacent third needles to partition them.
However, such a manner makes the finger needle further flexible laterally back and forth and causes damage to it.
A bed plate (21) has also been disposed behind the second needle (23) in place of the finger needle to support the backing fabric together with piles tufted in it, as shown in FIG. 7.
In this manner, an interspace for arranging the needles (22,23) in a double or three lines longitudinally front and rear should be disposed between the bed plate (21) and the finger needle (20).
As a result, a valley (29) is formed between the bed plate (21) and the finger needle (20). The second needle (23) operates so as to force the backing fabric (11) in the valley (29). Especially, in the case of the backing fabric (11) of the polyester multifilament fabric, it is apt to be forced in the valley (29) by the second needle (23) because it is so flexible.
As a result, in the case of the backing fabric (11) of the polyester multifilament fabric, the transverse pucker (32) is apt to rise in it, shown as in FIG. 7. It is also well known as a way to increase the density of the pile of the tufted carpet to shift the needles laterally back and forth by a half of needle gauge in each tufting cycle.
In this case, not only the needle but also the back stitch of the pile yarn operates so as to force the backing fabric (11) in the valley (29). Besides, height (H) of the pile can be varied in accordance with a distance (P) between the backing fabric (11) and the looper (28). And, when the backing fabric (11) is forced in the valley (29) between the bed plate (21) and the finger needle (20), the distance (P) between the backing fabric (11) and the looper (28) varies. As a result, it induces an irregulation in height (H) of the pile causing faults over the pile surface of the tufted carpet.
To eliminate these faults caused by the longitudinal pucker (30), the transverse pucker (32) and the irregulation in height (H) of the pile, attempts have been made to set the backing fabric (11) by treating it with a binding resin. These faults occur when using the polyester multifilament fabric in place of the flat yarn fabric for the backing fabric.
The use of the polyester multifilament fabric in place of the flat yarn fabric is required when a high tensile strength is required to the tufted carpet. And, in the case of the polyester multifilament fabric to which the high tensile strength is required, it is also typically required to increase both densities of warp and weft. However, if the high density polyester multifilament fabric is impregnated with a liquid binding resin, the warps and the wefts are so firmly fixed together at their intersections that the warps and the wefts can not easily slip aside when the needle threads into the polyester multifilament fabric in the tufting process. Thus, a backing fabric reinforced by impregnating with a liquid binding resin makes the tufting operation difficult.
Since the backing fabric is continuously transferred by feeding in the longitudinal direction. And, when the needle is threaded into the backing fabric, the backward and forward movement of the backing fabric at the threaded portion is stopped momentarily and partially by the needle. In such a situation, the backing fabric is loosened in the front side in the feeding direction (F) and is stretched in the opposite rear side. In other words, in the feeding direction (F), the needle is pushed out in the front side and is pulled out in the opposite rear side by the backing fabric.
As a result, the fine needle applied to the fine gauge tufting machine tends to be easily bent toward the feeding direction (F) of the backing fabric, fractured and damaged. However, in this situation, if the weft yarn slips aside pushed back by the needle and moves in the opposite direction against the fabric feeding, the reaction which operates from the weft yarn against the needle is to be decreased in accordance with the distance of the movement of the weft yarn, and therefore, the damage to the needle is reduced.
From the above-mentioned reasons, the manner of reinforcing the polyester multifilament fabric with a liquid binding resin is not suitable to avoid such problems as the longitudinal pucker (30), the transverse pucker (32) and the irregulation in height (H) of the pile, all of which occur in the fine gauge tufting machine. For reference, there are disclosed the backing fabrics reinforced with the binding resin in Japanese Patent No. 2727097 (Japanese Patent Laid Open No.2-161915), Japanese Utility Model Laid Open No. 54-82168 and Japanese Utility Model Publication No. 2-47875 (Japanese Utility Model Laid Open No.59-120982).
In the Japanese Patent No.272097 (Japanese Patent Laid Open No.2-161915), the coarse woven fabric comprised of monofilament yarns of 165 dtex to 8800 dtex, which is composed of thermo adhesible polymer and non thermo adhesible polymer is used for the backing fabric. After the tufting process, the backing fabric is heated to melt the thermo adhesible polymer, and then the pile is fixed on the backing fabric through the fused thermo adhesible polymer.
In the Japanese Utility Model Laid Open No. 54-82168, the pile is tufted to the backing fabric which is made of thermo adhesible fibers and the non-thermo adhesible fibers. After the tufting process, the backing fabric is heated to melt the thermo adhesible fibers, and the pile is then fixed on the backing fabric through the fused thermo adhesible fibers.
In the Japanese Utility Model Publication No. 2-47875 (Japanese Utility Model Laid Open No. 59-120982), the pile is tufted to the backing fabric which is made of conjugate-fiber of thermo adhesible polymers and non-thermo adhesible polymers. After the tufting process, the backing fabric is heated to melt the thermo adhesible polymers, and the pile is then fixed on the backing fabric through the fused thermo adhesible polymers. The manner of applying the thermo adhesible materials to the backing fabric is known.
However, in the prior art, none of the thermo adhesible materials is melted or fixed on anything before the tufting process. That is, before the tufting process, the thermo adhesible materials have not operated as an adhesive or a binding agent. Thus, these thermo adhesible materials do not damage the needle. On the other hand, these thermo adhesible materials do not reduce the flexibility of the backing fabric to a minimum before the tufting process, nor do they operate as a means for dissolving the problems of the longitudinal pucker (30), the transverse pucker (32) and the irregulation in height (H) of the pile, all of which occur in the tufting process.
Further, in Japanese Utility Model Laid Open No. 2-111372, there is disclosed a backing fabric woven of a flat ribbon monofilament yarn that is made of the matrix material of non-thermo adhesible polymer covered with the segment material of thermo adhesible polymer, where warp yarns and weft yarns are fixed together through the thermo adhesible polymer.
However, this backing fabric is used only for manufacturing artificial turf in which the pile is made of a flat ribbon monofilament yarn and is tufted with a rough gauge tufting machine. A pair of flat ribbon monofilament yarns, which are the warp yarn and the weft yarn crossing at the intersection of the fabric, become firmly fixed together by facing each other. Thus, such a backing fabric of which the warp yarn and the weft yarn are fixed can not be used in a fine gauge tufting machine.
Thus, the Japanese Utility Model Laid Open No.2-111372 does not neither teach nor suggest a manner of overcoming the problems of the longitudinal pucker (30), the transverse pucker (32) and the irregulation in height (H) of the pile, all of which occur in the tufting process where the multifilament fabric is used for backing fabric and a fine gauge tufting machine is used.
Of course, in the fine gauge tufting machine, it is theoretically possible to overcome the abovementioned problems by making the finger needle thinner and by making the needle and the pile yarn finer in accordance with the needle gauge.
However, in the case of using a fine pile yarn prepared with a finer needle gauge, even if such a thin tufted pile fabric as moquette, velvet, plush, corduroy, and the like, which are suitable to use for clothing, tablecloth, and the like, may be obtained. However, a thick tufted pile fabric, which is suitable for carpet to cover the floor, especially the floor of a vehicular passageway, can not be obtained. Thus, making the finger needle thinner and making the needle and the pile yarn finer will not produce a carpet that may be used in busy traffic areas, such as the floor of a vehicular passageway
Accordingly, it is an object of the present invention to provide a woven backing fabric that is made of multifilament yarns in warps and wefts, that overcomes the problems of the longitudinal pucker, the transverse pucker, the irregulation in height of the pile, the distortion of the pattern, and the like, all of which occurred in the tufting process where the multifilament fabric is used for the backing fabric and the fine gauge tufting machine, of which the needle gauge of less than {fraction (1/12)} inch is used. It is a further object of the present invention to provide a carpet that is tufted by using a fine gauge tufting machine, of which the needle gauge is less than {fraction (1/12)} inch, and by applying a thick pile yarn of 800-6000 dtex, and improved in the tensile strength and the dimensional stability so as to be suitable to cover the busy traffic areas, such as the floor of a vehicular passageway.